


Concrete

by tsunaide



Category: Haikyuu!!
Genre: Action, Alternate Universe - Detectives, Alternate Universe - Lawyers, Attempted Murder, Crimes & Criminals, M/M, Minor Violence, Romance, Slow Burn
Language: English
Status: In-Progress
Published: 2017-10-19
Updated: 2017-10-19
Packaged: 2019-01-20 01:35:02
Rating: Mature
Warnings: Creator Chose Not To Use Archive Warnings
Chapters: 1
Words: 3,677
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/12422304
Author URL: https://archiveofourown.org/users/tsunaide/pseuds/tsunaide
Summary: Hinata Shouyou wasn't the best graduate from Police Academy, but he's made it to his dream team nonetheless. He'll prove himself no matter what, and certainly has no time to constantly fight with his rival. Kageyama Tobio was definitely hailed as a king in his class. Transferring to the Karasuno Investigative Unit 1 was no surprise to him. But now they're stuck dealing with secretly uncovering a highly-publicized attempted murder, undercover missions, risking their lives, and worst of all... each other.





	Concrete

**Author's Note:**

> HELLO ALL! This is my first Haikyuu!! fic, and while I'm super excited to write this... I'll admit that I'm nervous too. It's been /years/ since I've written any fanfic so I feel rusty. I hope you enjoy this action/crime/thriller thing that I concocted. It's a combination of several of my favourite fandoms like Ace Attorney, Detective Conan, and Toshokan Sensou. The whole story has been planned out and I hope everything works out in my writing process. 
> 
> Main ship is KageHina but I'm sprinkling in some other ships as well.
> 
> Oh yeah! And if you're not familiar with Tough Mudder, it's a hardcore obstacle race held in North America. I know we're in Japan but... let's just imagine that this town organized one as well. 
> 
> So without further ado... Here's Concrete.

 

_Prologue_

 

If Hinata had to take a guess, he’d probably been locked up for a good three hours at this point. The shuttered window was no longer leaking in sunlight and it was only a matter of time before the door of death opened. The redhead could only dry heave now; there was nothing left in his stomach to puke. He had a weak stomach in the first place, so when he came to in this barren room Hinata had immediately hurled once he realized what had happened.

 

There was no way he was going to survive this ordeal. Sure, the detective had been in many dangerous situations as a member of the law enforcement, but being nabbed and locked up took it to an entirely new level. Whoever had locked him in here would hurt him  _ somehow _ . 

 

If he had simply let that photo go…  

 

But there was no way he wouldn’t have pursued- he was a detective after all. There wouldn’t be a single parallel universe where Hinata didn’t try to uncover the truth. Despite that, he knew he had fucked up somewhere. Perhaps if he had just trusted his partner… or maybe if he trusted him too much? God damn it. At this point, Hinata was grasping at straws for something to blame this dismal fate on.

 

He really only had himself to blame. Negligence for his own safety was traded for the safety of the case. As the severity of the situation sank in, the edges of his vision blurred and his heart was bursting out of his chest. Hinata couldn’t breathe. A few tears escaped and they fell helplessly to the floor as his hands remained uselessly cuffed to the window bars.

 

Hinata Shouyou was going to die.  
  


* * *

 

_The Present_

 

Hinata Shouyou was dying. And by dying, he meant that he was gripping monkey bars greased with butter and mud, praying to god that he wouldn’t slip and plunge into the brown icy mud water below. His hands felt as if they were going to slip any second.

 

Soggy dirt drenched every inch of his clothes.The previous Tough Mudder obstacle had involved a pool of mud water. The chill wind was slowly drying and caking grime onto his skin, and he prayed that he wouldn’t get a cold the next day. The detective took a deep breath to slow his racing heart and focused on the task ahead of him. Hinata reminded himself that he had to finish this course in the top numbers.

 

He cursed as his swing left him hanging by one hand, as the outstretched one slipped from the next bar. His fear of being dunked into the icy depths below was making his palms prickle and sweat.

 

_ Dear Body, you’re not helping. Sincerely, Shouyou. _

He tried to grab the bar again, and managed to somehow hold onto the slippery metal. He slowly and methodically made his way to the other end of the platform. Just a couple more miles to go until the last challenge. 

 

Although these courses were usually tackled in teams, Hinata didn't feel awkward or nervous being a solo Tough Mudder. Karasuno’s Tough Mudder was known for being full of soloers.  Plus, everyone was willing to lend a hand when you were struggling to climb up a wall anyways. Since most of the participants were members of the law enforcement, everyone was rather fit. But that didn't mean anything. He wasn't going to lose. 

 

Hinata took off to the next obstacle.

 

About halfway left, he realized that he was running behind someone familiar, wearing a mud-spattered blue shirt and black shorts. It was someone who he had passed and been passed by several times. The ginger stared at the back of a tall male- all broad shoulders, strong calves, and long limbs. Hinata frowned to himself in jealousy of the guy’s physique.

 

Feeling a flame of competitiveness burn within him, he picked up his pace to pass the stranger and felt his lungs burning in protest. Even though Hinata was fit, this 12 mile obstacle race was no joke. His muscles felt like he just climbed a mountain and climbed back down. But Hinata felt like he had a lot to prove; he didn’t graduate at the top of his class in Police Academy, yet still made his way to Karasuno Crime Investigation Unit 1 from the Yukigaoka Police Force. Tomorrow was his first day, and this marathon was part of his pledge to show the world just how good of a detective he could be. That, and being 180 centimetres tall definitely did not give that guy an advantage over Hinata here.

 

No height complex here. Nope.

 

After a few minutes, he saw a dark figure out of the corner of his eye pass him. Again. Irritated, Hinata picked up his pace as well. At this point, he had to weave through the participants aggressively, though there weren’t many since they were near the front of the crowd. He had to put as much distance between them as possible.

 

“Excuse me, sorry…” Hinata muttered and panted to no one in particular. He quickly scanned around and saw that the guy was keeping up with him. They were now the sole runners in the near vicinity, and he knew that this weird rivalry was definitely not all in his head. Hinata broke into a sprint and felt like his body was going to combust. It was over. His limbs were going to give out, but he had to beat this asshole if it was the last thing he did. 

 

Hinata nearly cried with joy as they approached the last obstacle marker. Mr. Grumpy was running at top speed too, and the Everest finally came into view. It was a quarter pipe slicked with (surprise) grease and mud, but there was no one waiting to hoist anyone up at the top. They had to do this alone... or help each other. Judging from the way they were racing each other, Hinata was pretty sure this was a one man mission. 

 

“Any chance you'd help me with this?” The detective said to the stranger. 

 

“No way in hell,” the guy turned to him with an expression that could kill. 

 

Woah. The glittering blue eyes staring back at him had him frozen for a few seconds. Those had to be contacts right? The stranger’s sharp features and expression made for an extremely haughty and handsome face. A few words came to mind immediately. Stuck-up royalty. Hinata felt his palms prickle in nervousness. 

 

His examination came to a halt as the subject broke off into a sprint and attempted to scale the greasy pipe. Hinata let out a snort when Grumpy (as the redhead now called him) came a couple of inches short from the edge and slid back down to the bottom. 

 

Serves you right, dick.

 

Hinata took a deep breath and ran onto the pipe. He got about halfway before sliding back down, his shoes finding zero purchase on the surface. How the hell were they going to get up? He glanced quickly at Grumpy who was also standing at the base, staring up the off-white wall. What was he going to do?

 

Hinata broke into another sprint and prayed to god he’d somehow make it to the top. This time, he actually felt something- no, someone pushing him down. Falling flat onto his face as he slid down, he sputtered out a string of curse words. He could taste a bit of mud in his mouth.

 

“What the hell??” He looked up and saw Grumpy wearing a smile that really could not be classified as such. His face looked like it had contorted into a grimace, even though the corners of his mouth were upturned. 

 

“Did you really just use me for leverage on your way up?” Hinata hollered and stamped his foot as if he were 9 and not 24. He felt a new layer of grease coating his face and tried not to imagine if he had ingested any. 

 

“Thanks for the helping hand chibi,” Grumpy jeered and turned to continue on his way. Hinata held up a middle finger in silent defiance.

 

“OI! ASSHOLE! The least you could do is help me up too!”  

 

“Winners train, losers complain,” a voice growled in the distance.

 

Hinata took in a deep breath and hollered. “We can race each other to the finish line!!!” 

 

A chill wind was the only reply.

 

Convinced that the man was well on his way, the detective decided to give it another shot. He put a good couple of metres between him and the wall, and pumped his legs as hard as he could. He felt himself flying across the ground. The top of the wall was nearing his grasp but his progress was slowing. Just one more step. He was so close! 

 

His hand reached out to grab the edge of the wall even though Hinata knew he was off. Instead, he felt a warm palm instead. He nearly let go in surprise, but grabbed onto the wrist with his other hand. Grumpy hoisted Hinata up roughly over the edge of the wall and he tumbled over and rolled into his back. 

 

He did it. Well, they did it. 

 

Grumpy was peering down at him through his bangs with narrowed eyes and crossed arms. Hinata raised a questioning eyebrow and glared right back at him. 

 

“Let’s race.”

 

“What? Are you for real? I'm dying here!” Hinata sputtered incredulously. 

 

“Dead serious.”

 

“Okay fine, on the count of 3 then,” the detective said as he righted himself into a crouch.

 

Grumpy tensed.

 

“3. 2. 1.”

 

“Go!!!” He roared.

 

And then they flew.

 

* * *

  
  
  


Yesterday was possibly the worst idea he’d ever had in all of his short existence. Hinata massaged his sore lats with one hand as he closed his eyes and tried to get some rest on the train. Every part of his body hurt. His shoulders, his back, his calves, his abs… Just walking down the stairs to the station was brutal torture.

 

It was 7:30 a.m. and Hinata had passed out as soon as he got out of the shower. Washing all the mud and grease off himself from the marathon took a good 40 minutes, and the detective was pleasantly surprised that he didn’t pass out in the shower.

 

The race had ended in what looked like a tie between him and Grumpy, and Hinata had crashed to the floor as soon as he hit the finish line, screaming and groaning. He never got the guy’s name or found out what department he was part of (or if he was even in the force), which was pretty disappointing. The guy had disappeared before Hinata could remember to find him. Not that he really cared; the guy was a Grade A asshole. Totally not beautiful at all. His eyes were totally not a shade of dark royal blue, and Hinata was definitely not imagining what his lips felt like. Grumpy was a gross mud-caked dickhead. All Hinata wanted to do was beat him in a race and show him up.

 

They both finished within the top 20, and he was obviously not admiring the fact that Grumpy was in incredible shape… Alright, if he was completely honest, the guy looked like he stepped off a magazine. His mental cringe at the thought caused him to physically shake his head.

 

“Excuse me,” a voice grunted.

 

Hinata looked down and saw a bald and surly salaryman staring at him expectantly. 

 

“Oh! I’m sorry,” he said as he made room for the man to exit the train. As the businessman brushed past, Hinata saw something flutter to the ground. 

 

“ _ Now approaching, Karasuno Town Centre Station, _ ” the speakers announced.

 

“Crap! That’s my station!” 

 

Flustered, he quickly grabbed the paper, wait no, photo that the salaryman had dropped and dashed out of the train. Where was he? There was a throng of bodies flowing towards the gates, and he wasn’t tall enough to see above their heads. 

 

Damn it.

 

He pushed through the crowd and made his way through the gates. Sprinting up the stairs two at a time despite his protesting muscles, Hinata looked around wildly. Bald guy. Bald guy. No bald guy anywhere… 

 

There! Bald guy. Being hauled into a white van… wait. WHAT?!

 

Hinata instinctively grabbed for his gun, but he recalled he was in plainclothes today. He had returned all of his gear to his original department was left with nothing until Unit 1 provided him with equipment. He had never felt more naked in his life.

 

To his surprise, baldie didn’t look at all distressed as he was forced into the car. Like he was already prepared for this. When the side door slid closed, he caught sight of Hinata. Eyes widened in recognition, and the man shook his head slowly. 

 

The detective stammered in confusion and stared as the van began to peel away. His quickly grabbed his phone (nearly dropping it in the process) and snapped a photo of the license place. Cursing to himself as he noticed the time on his phone, he shoved the photo into his briefcase. Hinata dialed the non-emergency police line (it took him a few tries to get it right) and started a jog towards the police headquarters. 

 

“Hello? I’d like to report a suspicious incident…”  
  


* * *

 

 

Hinata stood in front of the doors to the Karasuno Crime Investigation Unit 1 office with sweaty palms and an irritated stomach. His greatest wish right now was for no puking to happen within the next hour. He was about to meet the members of the unit that he’d be dreaming of joining since high school. His idol, the legendary detective Little Giant, used to be on this unit. This was where he would prove it all. 

 

The 5 foot 7 ball of energy and sunshine burst into the office and immediately bowed deeply.

 

“ _ Shitsurei shimasu! _ ” Hinata greeted loudly. 

 

“Ah! You must be Hinata Shouyou,” a deep voice said. 

 

Hinata righted himself and came face to face with a mature-looking detective. His close-cropped hair, immaculate attire, and amicable expression screamed  _ leadership _ . 

 

“Y-yes!” He fidgeted and put on his brightest smile. 

 

“Sawamura Daichi, Captain of Unit 1,” he grinned and stuck out a hand for Hinata to shake, “but you can call me Daichi.” 

 

“Eh? Okay!” Hinata chuckled and bowed again, “Please take care of me Daichi-san!” 

 

“Uwah! Our new kouhai is such a cutie!” 

 

Hinata swung around to see a man about the height as him (thank god he wasn’t the shortest one here), with wild brown hair and a blonde cowlick smiling broadly at him. 

 

“Nishinoya Yuu!” He exclaimed as he swung an arm around Hinata’s shoulders, “Please call me senpai.” 

 

“You got it, senpai!” Hinata grinned. He immediately took a liking to the boisterous young man.

 

Another new face emerged from the doorway. Dressed in business casual, a silver-haired man smiled gently at him and waved. 

 

“Good morning. I'm Sugawara Koushi,” he said as he shook Hinata’s hand. “We’re so happy to have newcomers on the team.”

 

His smile never faded from his face and a blush crawled onto Hinata’s face at the man’s genuine sincerity. 

 

“Thank you so much!” 

 

“Alright alright, let’s not overwhelm our new recruits all at once.” Daichi pulled a whining Nishinoya off Hinata. Finally, he got a chance to survey his surroundings. 

 

A large glass window on the far wall, an open office concept, rows of cabinets, and an abundance of volleyball posters. Inner Hinata jumped with glee as he took in some of his favourite players on the wall. He would definitely fit in here. 

 

“Kageyama, Get over here!” Daichi called, “Your fellow newbie is here!” 

 

Hinata tilted his head in confusion. Someone else had also transferred into the unit at the same time as him? That was the first he had heard of this.

 

A tall figure entered his line of sight and stopped. Broad shoulders, piercing blue eyes, and a nasty frown. Hinata came face to face with his Tough Mudder rival, looking much cleaner than he was yesterday afternoon. He was wearing a light blue dress shirt and tie, looking even more like a model today. His bangs fell softly over his forehead, in comparison to the clumpy mess from before.

 

“Kageyama Tobio,” he muttered awkwardly and stuck out his hand. 

 

“Grumpy?” Hinata’s jaw dropped.

 

“Grumpy? My name is  _ Kageyama,”  _ he snorted. 

 

Hinata’s head whirled. He knew that it was extremely probable that his mysterious stranger was working in the Karasuno District, but this outcome was a pleasant surprise. 

 

_ I mean… nasty. A nasty surprise. _ Hinata corrected himself.

 

“You two know each other?” Daichi rubbed his chin.

 

“Not exactly…”

 

“Yes!” 

 

The pair looked at each other in barely disguised contempt. 

 

“So what is it?” Sugawara laughed and observed that the two made a good combination. Even though they were in disagreement, they seemed to be in sync. He would definitely bring this to Daichi’s attention, but by the way Daichi was nodding, he could tell that the captain already agreed.

 

“We met at the Tough Mudder yesterday…” Hinata rubbed the back of his head nervously and Kageyama looked away. 

 

“ _ Tough Mudder?! _ ” A new voice chirped. The newest detective to join the circle sported a shaved head and an intimidating visage. “You two took on the most notorious event of the year?”

 

“What is that supposed to mean?” Kageyama snapped. 

 

“Hehe… just surprised that you shrimps could manage that insane obstacle course. I guess we definitely got some promising new recruits, eh Daichi?” He nudged the captain. 

 

“This is Tanaka Ryunosuke, resident delinquent. He did the Tough Mudder in his first year as well, with Nishinoya,” Daichi explained.

 

They were interrupted as Asahi Azumane, a lanky detective with a man-bun and goatee, and Ennoshita Chikara arrived into the office. 

 

“Nice to meet you,” Hinata and Kageyama bowed to all their new coworkers as they were introduced. They were shown to their desks and Hinata wasn’t sure what to think when he found that he was sitting directly across from Kageyama. Hinata glowered back at the dark-haired man and turned his attention to setting up his computer.

 

This morning would be tedious, getting all his digital permissions set up. All his previous secure network connections had to be re-established, and the new databases had to be connected as well. He took a sip of his coffee that Nishinoya had gratefully brought to him in a borrowed mug from the office kitchen and sighed. He’d have to bring his own black volleyball mug tomorrow. The excitement of the morning was wearing off and exhaustion was kicking in. Hinata felt himself nodding off as he waited for his email to set up when he heard Tanaka from across the room.

 

“The Ushijima case right? Unit 2 are lucky bastards. I would’ve loved to take that one on,” Tanaka whined. 

 

“Well, they haven’t ruled out suicide yet,” Ennoshita mused. 

 

“Come on. We all saw the photos and the evidence. No way there wasn’t foul play,” Nishinoya proclaimed.

 

Photos… 

 

The word rang a bell in Hinata’s mind and he jolted awake. He had totally forgotten the photo from this morning! He unlatched his briefcase and rifled through the mess. Toothbrush… gum wrapper… postcard… Aha! The detective discretely pulled out the photo and flipped it over on his lap. It was a shot of four young men, all wearing sports jersey declaring  _ Shiratorizawa _ on the front. A redhead, a raven-haired man, a scary-looking brunette, and a guy with a buzzcut. Hinata frowned and tried to pinpoint where he had seen this brunette before. Was he a volleyball player?

 

He flipped the photo over and saw a scrawl of words.

 

_ I know it was one of you four _ . 

 

A chill ran up his spine, and the words struck Hinata as more than just ominous. Was this blackmail? He shoved the photo back into his case and latched it shut. It was too early in his time here to bring up something potentially frivolous. He’d bring this to the officer who had taken in his report this morning later today. 

 

Hinata yawned and stretched. The clock only read 10:03 a.m. and his stomach was already grumbling. He stood up in search of snacks, and caught sight of the television on the wall. 

 

“Next up, we have the newest report on the attempted murder of Ushijima Wakatoshi. The famous volleyball player was found in a comatose state in his Tokyo apartment…”

 

The detective stilled and stared at the photo of that same intimidating brunette blown up on national television, with glaring headlines announcing his death rolling across the screen. 

 

“Ushi...jima…” Hinata whispered and covered his mouth in shock. 

 

That photo was accusing someone of attempted  _ murder _ . 

  
  


* * *

 

 

Kageyama looked over at his colleague sitting in front of him, who was preoccupied with something under the table. Ever since they had been formally introduced this morning, the fellow rookie rubbed him the wrong way. Hinata Shouyou’s cheerful attitude and  _ sunshinyness  _ annoyed him. His head of unruly orange hair was too bright, and too messy. How was someone like him on the same team as him? 

 

He had a sneaking suspicion that Kageyama would be stuck dragging this deadweight around. 

 

If there was one thing he hated, it was definitely useless people. The one silver lining was that this guy was good in the physical department, at least. He had proven that at the obstacle course. Kageyama unofficially assigned him as the one who would be throwing his body around.

 

He grinned to himself at the thought of his brilliant scheme, and he observed as Hinata stood up and seemingly froze. The detective stared at the television for a good five minutes, even though Kageyama _ knew _ that the Ushijima headline was nothing special. It was a rerun of what was practically the same report yesterday. 

 

Weird… and suspicious.

 

His detective senses tingled.

 

What did Hinata Shouyou have to do with Ushijima Wakatoshi?  
  


**Author's Note:**

> Kudos and comments are veeery much appreciated. Let me know what you thought! 
> 
> P.S. Just a note to any of my IRL friends who may have found this fic... You better not troll me about this. ALL HAIL KAGEHINA.


End file.
